Project Summary Objectives: This proposal is written in direct response to a specific request for new therapeutic directions for neurodegenerative disease (Alzheimer's) treatment as well as the development of new animal models of neurodegenerative disease useful for monitoring the effects of new therapies on the dementing process. We plan to test a well-characterized small molecule peptide fragment, JM4 synthesized from erythropoietin for long-term therapy in three transgenic mouse models of neurodegenerative disease. We believe that part of the progression in Alzheimer's disease is related to protracted inflammatory processes and that our newly discovered potent Immunomodulatory compound, JM4 that appears to work through downregulation of the innate immune system may be beneficial. Our compound may or may not attack a root cause of Alzheimer's disease but if secondary inflammation is critical to onset or progression in this disorder, then our compounds may be of long-term benefit. Specific aims S.A.1: Determine the therapeutic effect of our small EPO peptide on three animal models of neurodegenerative disease and/or AD with different clinical and pathologic characteristics. The drug will be tested against the triple transgenic AD mouse model, a more aggressive 5xFAD beta-amyloid model and early on in a third model (P301S) where tau-mediated pathology, microglial activation and hind limb paresis are prominent. The functional effects of long-term therapy will be assessed using PBS sham-treated animals as controls. (Neurobehavioral assessment, time to disease onset, Kaplan- Meier survival curve, drug effect on preventing both ventricular enlargement and hippocampal atrophy. We will also employ immunohistochemistry and flow cytometric assays for determining the effects of therapy on microglial/macrophage immunoreactivity using MHCII, Lectin, Iba1, CD11b, CD11c, F4/80, on neurons (NeuN) using monoclonal antibodies for phosphorylated tau (AT8), conformational specific tau antibody (MC1), synaptophysin, 6E10 for -amyloid products and APP, and by ThioS staining). S.A. 2: Develop a refined animal model of dementia using both 5xFAD amyloid and P301S tau mice further encoded with an additional transgene specific for GFAP-luciferase. These enhanced neurodegenerative models can be followed long-term in single animals non-invasively from early childhood (asymptomatic) through disease onset to full-blown disease. Our pilot data indicates that the GFAP-luc/P301S tau animals will manifest markedly increased bioluminescence as they become symptomatic. Importantly, positive effects of therapy induced by our small JM4 EPO peptide, JM4 should be reflected by suppressed or greatly reduced bioluminescence when compared to bioluminescent levels in symptomatic sham treated animals. Controls for the bioluminescence studies will include immunohistochemistry for GFAP, Western Immunoblots for GFAP and RT-PCR of GFAP transcripts to control for message abundance and extent of bioluminescent signal. S.A. 3: In aged symptomatic 5xFAD or P301S tau animals, determine if interventional JM4 therapy (3 month) initiated at 6 or 9 months of age is as effective as chronic very long duration therapy in delaying onset or progression of the neurodegenerative process using the criteria enumerated in S.A. 1 and 2 (neurobehavioral, drug effect on degree of GFAP bioluminescence and immunohistochemical assessment). S.A. 4: Using IV administered radiolabeled JM4, determine JM4 blood-brain barrier permeability in normal mice (whole brain counts from post-perfused animals and as an alternate by microdialysis in hippocampus). Potential Impact on Veterans Health Care: There is a pressing need for a therapy for Alzheimer's disease where there is currently no effective treatment. The Alzheimer foundation states that if the dementing process could be slowed by 5 years, US health care costs for this condition would drop by 50%. lf this is true, the remarkable delays we have been observing in our novel compound (JM4) treated AD mice, while well short of a complete cure, could likely slow progression by 5 years or more. lf positive findings are consistently confirmed in the proposed animal studies, then it would be a clear cut indication that the immune response and its modulation in Alzheimer's are likely critical components of the puzzle, Our compounds appear to work like no other immunomodulating compounds described to date and we believe since it is a naturally occurring motif hidden within the human and animal EPO molecule, its efficacy will be favorable and side effect profile minimal.